A Numerical Analysis on Pullout Capacity of Batter Pile Groups in Sandy Soil

Abstract

Batter piles or raker piles are the piles driven in the soil at an inclination with the vertical to resist inclined forces or large lateral loads. Battered piles are widely utilized to support offshore buildings, towers, and bridges since these structures are risky due to the exposure to overturning moments resulting from winds, waves, and ship impact. This paper used a three-dimensional finite element analysis using PLAXIS 3D software to study the effect of several variables that affect the behavior of batter piles in a group under pullout loads. The study is conducted on a steel pipe pile model embedded in a dry sandy soil with three different relative densities (loose, medium, and dense sand) at different inclination angles and three embedment ratios L/D of 25, 37.5, and 50, respectively. The finite element model was carried out on a pile group of 2×1 with different configurations. The numerical results indicated that for all pile configurations, the pullout capacity of the batter pile group increased when the embedded ratio and relative density increased, and the maximum value was attained at a 20° batter angle. Furthermore, batter pile groups with BB (group with two battered piles) configuration of (-20°, +20°) gave a high resistance to the pullout load compared to other configurations of the pile group. In addition, pile Groups with battered piles marked the resistance to the pullout load more than pile groups that contain only the vertical piles.